title: Statin restores cardiac autonomic response to acute hypoxia in hypercholesterolaemia.
abstract: BACKGROUND
  Hypercholesterolaemia may alter cardiovascular autonomic function. We investigated the autonomic cardiovascular regulation during normoxia and hypoxia in familial isolated HC patients with or without statin treatment.
  
  
  METHODS
  Low (LF-RR) and high (HF-RR) components of spectral analysis of RR interval and systolic arterial pressure (LF-SAP) were obtained during 5 min of normoxia and isocapnic hypoxia (10% O(2) ) in 10 normotensive familial HC patients without medication, in seven HC patients after a 12-week treatment period with 40 mg of simvastatin (HC + SVT) and in eight matched normal volunteers (CO).
  
  
  RESULTS
  The HC patients had significant impairment of cardiac autonomic modulation parameters compared with CO at normoxia, which was maintained or even accentuated during hypoxia; these parameters included lower total variance of RR, increased normalized LF-RR, decreased normalized HF-RR, increased LF-RR/HF-RR ratio, higher LF-SAP component and reduced α index. However, the HC + SVT group had a significant improvement in all parameters: the LF-RR and LF-SAP decreased (indicating a decrease in cardiac and vascular sympathetic activity), the HF-RR increased (indicating an increase in parasympathetic activity) and the spontaneous baroreflex sensitivity improved. These changes were detected at normoxia and were maintained during hypoxia.
  
  
  CONCLUSIONS
  Our data are the first to show that isolated HC is characterized by an increase in cardiac and vasomotor sympathetic drive, a decrease in cardiac vagal modulation and baroreflex impairment during normoxia and hypoxia. In addition, our data suggest that statin treatment has a potential role in restoring the physiological cardiovascular autonomic control at baseline and during cardiovascular challenge.
authors.affiliation: Instituto do Coração (InCor), Universidade de São Paulo, São Paulo, Brazil; Universidade Federal de São Paulo (UNIFESP), São Paulo, Brazil; Universidade Federal da Paraíba, João Pessoa, Brazil.
authors.forename: Maria S
authors.initials: MS
authors.lastname: Brasileiro-Santos
authors.forename: José A S
authors.initials: JA
authors.lastname: Barreto-Filho
authors.forename: Raul D
authors.initials: RD
authors.lastname: Santos
authors.forename: Ana P M
authors.initials: AP
authors.lastname: Chacra
authors.forename: Carine Teles
authors.initials: CT
authors.lastname: Sangaleti
authors.forename: Gisele
authors.initials: G
authors.lastname: Alvez
authors.forename: Otavio Coelho
authors.initials: OC
authors.lastname: Bezerra
authors.forename: Luiz Aparecido
authors.initials: LA
authors.lastname: Bortoloto
authors.forename: Maria C
authors.initials: MC
authors.lastname: Irigoyen
authors.forename: Fernanda M
authors.initials: FM
authors.lastname: Consolim-Colombo
mesh_terms: D000208:Acute Disease; D000328:Adult; D001341:Autonomic Nervous System / Q000187:drug effects*; D017704:Baroreflex / Q000187:drug effects; D001794:Blood Pressure / Q000187:drug effects; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000627:therapeutic use*; D006938:Hyperlipoproteinemia Type II / Q000188:drug therapy / Q000503:physiopathology*; D000860:Hypoxia / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D012018:Reflex / Q000187:drug effects; D019821:Simvastatin / Q000627:therapeutic use*; D055815:Young Adult
chemical_list: D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D019821:Simvastatin
keywords: Autonomic nervous system; blood pressure; hypercholesterolaemia; hypoxia; simvastatin